 | This template is used on approximately 324,000 pages, or roughly 1% of all pages. To avoid major disruption and server load, any changes should be tested in the template's /sandboxor/testcases subpages, or in your own user subpage. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
This template tests whether the first unnamed parameter is not an empty string and returns it if it is not empty. Otherwise it returns the second unnamed parameter.
This is useful when the first parameter is a {{#invoke: }} of a Lua module that may return a value or nothing. Because it uses the {{#invoke: }} just once, it simplifies the coding of infoboxes, for example.
The optional third and fourth unnamed parameters provide a prefix and a suffix for the first parameter when returned. This enables the designer to construct more complex templates that still only use one invoke of a Lua module.
{{If then show|{{#invoke:WikidataIB|getValue|P26|qid=Q151973|fwd=ALL|osd=no}}|unmarried}} → Elizabeth Taylor, Sybil Christopher, Suzy Miller, Elizabeth Taylor, Sally Burton 
{{If then show|{{#invoke:WikidataIB|getValue|P26|qid=Q905|fwd=ALL|osd=no}}|unmarried}} → unmarriedA value in an infobox can be designed to be wrapped in a microformat if the wikidata call is not empty:
{{if then show | {{#invoke:WikidataIB | getValue | rank=best |P19 |name=birth_place |qid={{{qid|}}} |suppressfields={{{suppressfields|}}} |fetchwikidata={{{fetchwikidata|}}} |noicon={{{noicon|}}} | {{{birth_place|}}} }} || <span class="birthplace"> | </span>}}|birth_place=London), the code will return <span class="birthplace">London</span>.<span class="birthplace">New York</span>.A table can be designed to display a row only when a particular property of the article exists on Wikidata.
{| class="wikitable"
|-
! scope="col" style="width:15em;" | Label
! scope="col" style="width:36em;" | Value
{{If then show|{{#invoke:WikidataIB|getValue|P26|qid=Q151973|fwd=ALL|osd=no}}||<tr><th>{{#invoke:WikidataIB|getLabel|P26|qid=Q151973}}</th><td>|</td></tr>}}
|}
| Label | Value |
|---|---|
| spouse | Elizabeth Taylor, Sybil Christopher, Suzy Miller, Elizabeth Taylor, Sally Burton |
{| class="wikitable"
|-
! scope="col" style="width:15em;" | Label
! scope="col" style="width:36em;" | Value
{{If then show|{{#invoke:WikidataIB|getValue|P26|qid=Q905|fwd=ALL|osd=no}}||<tr><th>{{#invoke:WikidataIB|getLabel|P26|qid=Q905}}</th><td>|</td></tr>}}
|}
| Label | Value |
|---|
{{#invoke: of a Lua module that returns a value for which a specific exception is required.|code= and uses a formatter url as |url= to construct a link to the external resource, which uses the code as display.
